1.Assessment of respiratory protection competency of staff in healthcare facilities
Hui-Xue JIA ; Xi YAO ; Mei-Hua HU ; Bing-Li ZHANG ; Xin-Ying SUN ; Zi-Han LI ; Ming-Zhuo DENG ; Lian-He LU ; Jie LI ; Li-Hong SONG ; Jian-Yu LU ; Xue-Mei SONG ; Hang GAO ; Liu-Yi LI
Chinese Journal of Infection Control 2024;23(1):25-31
		                        		
		                        			
		                        			Objective To understand the respiratory protection competency of staff in hospitals.Methods Staff from six hospitals of different levels and characteristics in Beijing were selected,including doctors,nurses,medical technicians,and servicers,to conduct knowledge assessment on respiratory protection competency.According to exposure risks of respiratory infectious diseases,based on actual cases and daily work scenarios,content of respira-tory protection competency assessment was designed from three aspects:identification of respiratory infectious di-seases,transmission routes and corresponding protection requirements,as well as correct selection and use of masks.The assessment included 6,6,and 8 knowledge points respectively,with 20 knowledge points in total,all of which were choice questions.For multiple-choice questions,full marks,partial marks,and no mark were given respective-ly if all options were correct,partial options were correct and without incorrect options,and partial options were correct but with incorrect options.Difficulty and discrimination analyses on question of each knowledge point was conducted based on classical test theory.Results The respiratory protection competency knowledge assessment for 326 staff members at different risk levels in 6 hospitals showed that concerning the 20 knowledge points,more than 60%participants got full marks for 6 points,while the proportion of full marks for other questions was relatively low.Less than 10%participants got full marks for the following 5 knowledge points:types of airborne diseases,types of droplet-borne diseases,conventional measures for the prevention and control of healthcare-associated infec-tion with respiratory infectious diseases,indications for wearing respirators,and indications for wearing medical protective masks.Among the 20 knowledge questions,5,1,and 14 questions were relatively easy,medium,and difficult,respectively;6,1,4,and 9 questions were with discrimination levels of ≥0.4,0.30-0.39,0.20-0.29,and ≤0.19,respectively.Conclusion There is still much room for hospital staff to improve their respiratory protection competency,especially in the recognition of diseases with different transmission routes and the indications for wearing different types of masks.
		                        		
		                        		
		                        		
		                        	
2.Prevention and treatment of monkeypox in pregnant women
Yeqin DENG ; Ying HONG ; Bin ZHANG ; Yang GAO ; Yanming WAN ; Ronghua XU ; Yaling ZONG
Journal of Public Health and Preventive Medicine 2024;35(5):130-133
		                        		
		                        			
		                        			Using China National Knowledge Infrastructure, Wanfang, and PubMed database, literature search was conducted with the keywords “pregnancy” and “monkeypox”, and 27 related research articles were selected for analysis. Through a comprehensive review of the related literature, we aim to improve our knowledge of this viral disease, better our prevention, treatment and responses to future monkeypox outbreaks in China, so as to better protect the safety of mothers and infants. Maternal monkeypox can be prevented and controlled, if active and effective measures are taken in time. Drawing on the experience and lessons from monkeypox outbreaks at home and abroad, it is suggested that hospitals and public health agencies at all levels should raise awareness, and establish an effective emergency preparedness system for the prevention and control of potential future outbreaks.
		                        		
		                        		
		                        		
		                        	
3.Nanomaterial-based Therapeutics for Biofilm-generated Bacterial Infections
Zhuo-Jun HE ; Yu-Ying CHEN ; Yang ZHOU ; Gui-Qin DAI ; De-Liang LIU ; Meng-De LIU ; Jian-Hui GAO ; Ze CHEN ; Jia-Yu DENG ; Guang-Yan LIANG ; Li WEI ; Peng-Fei ZHAO ; Hong-Zhou LU ; Ming-Bin ZHENG
Progress in Biochemistry and Biophysics 2024;51(7):1604-1617
		                        		
		                        			
		                        			Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment. 
		                        		
		                        		
		                        		
		                        	
4.Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients (version 2024)
Yao LU ; Yang LI ; Leiying ZHANG ; Hao TANG ; Huidan JING ; Yaoli WANG ; Xiangzhi JIA ; Li BA ; Maohong BIAN ; Dan CAI ; Hui CAI ; Xiaohong CAI ; Zhanshan ZHA ; Bingyu CHEN ; Daqing CHEN ; Feng CHEN ; Guoan CHEN ; Haiming CHEN ; Jing CHEN ; Min CHEN ; Qing CHEN ; Shu CHEN ; Xi CHEN ; Jinfeng CHENG ; Xiaoling CHU ; Hongwang CUI ; Xin CUI ; Zhen DA ; Ying DAI ; Surong DENG ; Weiqun DONG ; Weimin FAN ; Ke FENG ; Danhui FU ; Yongshui FU ; Qi FU ; Xuemei FU ; Jia GAN ; Xinyu GAN ; Wei GAO ; Huaizheng GONG ; Rong GUI ; Geng GUO ; Ning HAN ; Yiwen HAO ; Wubing HE ; Qiang HONG ; Ruiqin HOU ; Wei HOU ; Jie HU ; Peiyang HU ; Xi HU ; Xiaoyu HU ; Guangbin HUANG ; Jie HUANG ; Xiangyan HUANG ; Yuanshuai HUANG ; Shouyong HUN ; Xuebing JIANG ; Ping JIN ; Dong LAI ; Aiping LE ; Hongmei LI ; Bijuan LI ; Cuiying LI ; Daihong LI ; Haihong LI ; He LI ; Hui LI ; Jianping LI ; Ning LI ; Xiying LI ; Xiangmin LI ; Xiaofei LI ; Xiaojuan LI ; Zhiqiang LI ; Zhongjun LI ; Zunyan LI ; Huaqin LIANG ; Xiaohua LIANG ; Dongfa LIAO ; Qun LIAO ; Yan LIAO ; Jiajin LIN ; Chunxia LIU ; Fenghua LIU ; Peixian LIU ; Tiemei LIU ; Xiaoxin LIU ; Zhiwei LIU ; Zhongdi LIU ; Hua LU ; Jianfeng LUAN ; Jianjun LUO ; Qun LUO ; Dingfeng LYU ; Qi LYU ; Xianping LYU ; Aijun MA ; Liqiang MA ; Shuxuan MA ; Xainjun MA ; Xiaogang MA ; Xiaoli MA ; Guoqing MAO ; Shijie MU ; Shaolin NIE ; Shujuan OUYANG ; Xilin OUYANG ; Chunqiu PAN ; Jian PAN ; Xiaohua PAN ; Lei PENG ; Tao PENG ; Baohua QIAN ; Shu QIAO ; Li QIN ; Ying REN ; Zhaoqi REN ; Ruiming RONG ; Changshan SU ; Mingwei SUN ; Wenwu SUN ; Zhenwei SUN ; Haiping TANG ; Xiaofeng TANG ; Changjiu TANG ; Cuihua TAO ; Zhibin TIAN ; Juan WANG ; Baoyan WANG ; Chunyan WANG ; Gefei WANG ; Haiyan WANG ; Hongjie WANG ; Peng WANG ; Pengli WANG ; Qiushi WANG ; Xiaoning WANG ; Xinhua WANG ; Xuefeng WANG ; Yong WANG ; Yongjun WANG ; Yuanjie WANG ; Zhihua WANG ; Shaojun WEI ; Yaming WEI ; Jianbo WEN ; Jun WEN ; Jiang WU ; Jufeng WU ; Aijun XIA ; Fei XIA ; Rong XIA ; Jue XIE ; Yanchao XING ; Yan XIONG ; Feng XU ; Yongzhu XU ; Yongan XU ; Yonghe YAN ; Beizhan YAN ; Jiang YANG ; Jiangcun YANG ; Jun YANG ; Xinwen YANG ; Yongyi YANG ; Chunyan YAO ; Mingliang YE ; Changlin YIN ; Ming YIN ; Wen YIN ; Lianling YU ; Shuhong YU ; Zebo YU ; Yigang YU ; Anyong YU ; Hong YUAN ; Yi YUAN ; Chan ZHANG ; Jinjun ZHANG ; Jun ZHANG ; Kai ZHANG ; Leibing ZHANG ; Quan ZHANG ; Rongjiang ZHANG ; Sanming ZHANG ; Shengji ZHANG ; Shuo ZHANG ; Wei ZHANG ; Weidong ZHANG ; Xi ZHANG ; Xingwen ZHANG ; Guixi ZHANG ; Xiaojun ZHANG ; Guoqing ZHAO ; Jianpeng ZHAO ; Shuming ZHAO ; Beibei ZHENG ; Shangen ZHENG ; Huayou ZHOU ; Jicheng ZHOU ; Lihong ZHOU ; Mou ZHOU ; Xiaoyu ZHOU ; Xuelian ZHOU ; Yuan ZHOU ; Zheng ZHOU ; Zuhuang ZHOU ; Haiyan ZHU ; Peiyuan ZHU ; Changju ZHU ; Lili ZHU ; Zhengguo WANG ; Jianxin JIANG ; Deqing WANG ; Jiongcai LAN ; Quanli WANG ; Yang YU ; Lianyang ZHANG ; Aiqing WEN
Chinese Journal of Trauma 2024;40(10):865-881
		                        		
		                        			
		                        			Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.
		                        		
		                        		
		                        		
		                        	
5.Effects of 2 650 MHz radiofrequency radiation on the behavior and hippocampal neurotransmitter release of mice
Yujie LIU ; Jun WANG ; Keqin LI ; Chenxu CHANG ; Ying LIU ; Hongyan ZUO ; Yang LI ; Hong YANG ; Yanhui HAO ; Hua DENG
Chinese Journal of Radiological Medicine and Protection 2024;44(5):354-360
		                        		
		                        			
		                        			Objective:To investigate the effects of 2 650 MHz radiofrequency (RF) exposure on the behavior and neurotransmitter release of mice.Methods:Adult male C57BL/6N mice were divided into a normal control (CON) group and a radiofrequency radiation (RFR) group using the random number table method. The mice in the RFR group were subjected to single-dose whole-body exposure to a uniform 2 650 MHz RF electromagnetic field for 3 h. During the RF exposure, the field strength in the effective working area of the RF radiation platform was measured using an electromagnetic radiation analyzer, and the changes in the anal temperature of the mice were monitored using an optical fiber thermometer. Moreover, the changes in the cognition, social interaction, and emotion of the mice were determined through the new object recognition test, social preference test, and open field test. Finally, the changes in the hippocampal neurotransmitter release levels of the mice were detected using microdialysis sampling and mass spectrometry, and the changes in the hippocampal tissue structure and ultrastructure were observed via microscopy.Results:Under the test conditions, RF radiation improved the anal temperature of the mice, with a maximum increasing amplitude of 0.61℃, falling within the range of thermal safety. The mice in the RFR group experienced a significant decrease in the frequency and time for exploring new objects ( t=4.50, 2.53, P < 0.05) in the new object recognition test, a significant decrease in the frequency ( t=0.08, P<0.01) and time ( t=0.03, P<0.05) for exploring other mice in the social preference test, and no significant change in the frequency and time for exploring the central area ( P > 0.05) in the open field test. Compared to the CON group, the RFR group showed an increase in the release of 5-hydroxytryptamine (5-HT) ( t=-2.56, P < 0.05) and a decrease in the release of acetylcholine (ACh) ( t=2.21, P < 0.05), no significant difference in the release of glutamate (Glu) and γ-aminobutyric acid (GABA) ( P > 0.05), and no evident damage to the hippocampal tissue and structure and synaptic ultrastructure. Conclusions:2 650 MHz RF radiation may induce cognitive impairment and abnormal social preference in mice, which is attributed to neuronal dysfunctions and neurotransmitter release disorders under RF exposure.
		                        		
		                        		
		                        		
		                        	
6.Mediating effect of moral sensitivity on moral dilemma and professional identity of clinical nurses
Shan HUANG ; Ying DENG ; Yangshuang ZHAO ; Hong GUO
Chinese Journal of Modern Nursing 2024;30(12):1625-1631
		                        		
		                        			
		                        			Objective:To explore the mediating effect of clinical nurses' moral sensitivity between moral dilemma and professional identity.Methods:A total of 349 clinical nurses from Beijing Hospital were selected as subjects in May 2023 by the convenient sampling method. Nurses were investigated by general data questionnaire, Nurses Professional Identity Scale, Moral Distress Scale-Revised Version into Chinese (MDS-R-CV) and Moral Sensitivity Questionnaire-Revised Version into Chinese (MSQR-CV). Spearman correlation analysis was used to explore the correlation between clinical nurses' professional identity, moral dilemma and moral sensitivity. AMOS 26.0 statistical software was used to establish a mediating effect model and Bootstrap method was used to test the mediating effect.Results:A total of 349 questionnaires were collected, and after excluding questionnaires with a response time of less than 3 minutes, 341 valid questionnaires remained. The professional identity score of 341 clinical nurses was (109.19±21.03), the total score of moral dilemma was 45.00 (22.50, 85.00) and the total score of moral sensitivity was (42.61±6.46). The results of correlation analysis showed that the moral dilemma of clinical nurses was negatively correlated with moral sensitivity and professional identity ( P<0.05), and moral sensitivity was positively correlated with professional identity ( P<0.01). The mediating effect analysis showed that nurses' moral sensitivity played a partial mediating role in moral dilemma and professional identity, and the effect ratio was 14.43%. Conclusions:The moral sensitivity of clinical nurses plays a partial mediating role in moral dilemmas and professional identity. It is necessary to improve the moral sensitivity of clinical nurses, alleviate moral dilemmas and enhance professional identity, in order to provide high-quality nursing services for patients.
		                        		
		                        		
		                        		
		                        	
7.A multi-center epidemiological study on pneumococcal meningitis in children from 2019 to 2020
Cai-Yun WANG ; Hong-Mei XU ; Gang LIU ; Jing LIU ; Hui YU ; Bi-Quan CHEN ; Guo ZHENG ; Min SHU ; Li-Jun DU ; Zhi-Wei XU ; Li-Su HUANG ; Hai-Bo LI ; Dong WANG ; Song-Ting BAI ; Qing-Wen SHAN ; Chun-Hui ZHU ; Jian-Mei TIAN ; Jian-Hua HAO ; Ai-Wei LIN ; Dao-Jiong LIN ; Jin-Zhun WU ; Xin-Hua ZHANG ; Qing CAO ; Zhong-Bin TAO ; Yuan CHEN ; Guo-Long ZHU ; Ping XUE ; Zheng-Zhen TANG ; Xue-Wen SU ; Zheng-Hai QU ; Shi-Yong ZHAO ; Lin PANG ; Hui-Ling DENG ; Sai-Nan SHU ; Ying-Hu CHEN
Chinese Journal of Contemporary Pediatrics 2024;26(2):131-138
		                        		
		                        			
		                        			Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]
		                        		
		                        		
		                        		
		                        	
8.The Uptake and Distribution Evidence of Nano-and Microplastics in vivo after a Single High Dose of Oral Exposure
Tao HONG ; Wei SUN ; Yuan DENG ; Da Jian LYU ; Hong Cui JIN ; Long Ying BAI ; Jun NA ; Rui ZHANG ; Yuan GAO ; Wei Guo PAN ; Sen Zuo YANG ; Jun Ling YAN
Biomedical and Environmental Sciences 2024;37(1):31-41
		                        		
		                        			
		                        			Objective Tissue uptake and distribution of nano-/microplastics was studied at a single high dose by gavage in vivo.Methods Fluorescent microspheres (100 nm, 3 μm, and 10 μm) were given once at a dose of 200 mg/(kg·body weight). The fluorescence intensity (FI) in observed organs was measured using the IVIS Spectrum at 0.5, 1, 2, and 4 h after administration. Histopathology was performed to corroborate these findings.Results In the 100 nm group, the FI of the stomach and small intestine were highest at 0.5 h, and the FI of the large intestine, excrement, lung, kidney, liver, and skeletal muscles were highest at 4 h compared with the control group (P < 0.05). In the 3 μm group, the FI only increased in the lung at 2 h (P < 0.05). In the 10 μm group, the FI increased in the large intestine and excrement at 2 h, and in the kidney at 4 h (P < 0.05). The presence of nano-/microplastics in tissues was further verified by histopathology. The peak time of nanoplastic absorption in blood was confirmed.Conclusion Nanoplastics translocated rapidly to observed organs/tissues through blood circulation;however, only small amounts of MPs could penetrate the organs.
		                        		
		                        		
		                        		
		                        	
9.Imaging assessment of the activity and treatment efficacy of thyroid associated ophthalmopathy
Yu LIU ; Mengting LI ; Hong CHEN ; Wei LIU ; Ying DING ; Li ZHANG ; Yinqian DENG ; Huanyu CHEN ; Min ZHAO ; Xiaotian XIA ; Wei CAO
Chinese Journal of Nuclear Medicine and Molecular Imaging 2024;44(10):628-632
		                        		
		                        			
		                        			Thyroid associated ophthalmopathy (TAO) is an organ-specific autoimmune disease. TAO is clinically classified into active and inactive stage, and the accurate judgment is the key point of treatment choice. Clinical activity score (CAS) is often used for the assessment of TAO activity, which is subjective to some extent. With the development of imaging techniques, ultrasonography, CT, MRI and radionuclide imaging have gradually been applied into the diagnosis and treatment of TAO. What′s more, the imaging is an important complement to CAS from the aspects of anatomical and functional metabolism, which can better assess the activity and the therapy response of TAO. The clinical value of medical imaging in activity and treatment efficacy evaluation of TAO is reviewed in this article.
		                        		
		                        		
		                        		
		                        	
10.Chronic Injury of Mice Bone Marrow Multipotent Hematopoietic Progenitor Cells Induced by Ionizing Radiation.
Ying-Ying LUAN ; Juan YANG ; Shuo YANG ; Han-Cheng FAN ; Zi-Hao YANG ; Jin-Fu ZHANG ; Rong DENG ; Hua WANG ; Hui-Hong ZENG ; Li-Jian SHAO
Journal of Experimental Hematology 2023;31(3):871-879
		                        		
		                        			OBJECTIVE:
		                        			To explore the chronic injury and its possible mechanism of ionizing radiation on multipotent hematopoietic progenitor cells (MPPs) by determining the related indicators of MPPs in bone marrow of mice post-radiation.
		                        		
		                        			METHODS:
		                        			Sixteen C57BL/6 adult mice were randomly divided into normal control and irradiation groups, 8 mice in each group. The mice in irradiation group were exposed to 6 Gy X-ray. The proportion of bone marrow MPPs, their apoptosis and proliferation 2 months after irradiation were detected by flow cytometry. Mitochondrial activity and levels of reactive oxygen species (ROS) in each MPPs population were detected by Mitotracker Red and DCFDA probes, and the senescent state of MPPs in the bone marrow was analyzed.
		                        		
		                        			RESULTS:
		                        			Ionizing radiation could reduce the proportion of MPPs in mouse bone marrow. The proportions and numbers of MPP1, MPP3 and MPP4 in the bone marrow were significantly decreased after whole-body irradiation with 6 Gy X-ray (P<0.05). In addition, radiation significantly reduced the colony-forming capacity of MPPs in bone marrow (P<0.05), the proportions of apoptotic cells in the MPP1 and MPP4 cell populations increased significantly in the bone marrow (P<0.05). The activity of mitochondria was significantly reduced in the bone marrow MPP2, MPP3 and MPP4 cell populations compared with that of the control group (P<0.05). It was also found that the radiation could significantly increase the ROS levels of MPPs in bone marrow, and the content of ROS in the MPP2, MPP3 and MPP4 cell population of the bone marrow was significantly increased(P<0.05). The senescent cells ratios of MPP1, MPP3 and MPP4 cells in the bone marrow after irradiation were significantly higher than those in the control group (P<0.05).
		                        		
		                        			CONCLUSION
		                        			Ionizing radiation can cause chronic MPPs damage in mice, which is closely associated with persistent oxidative stress, cells apoptosis, and cellular senescence.
		                        		
		                        		
		                        		
		                        			Mice
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		                        			Animals
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		                        			Bone Marrow
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		                        			Reactive Oxygen Species
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		                        			Mice, Inbred C57BL
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		                        			Hematopoietic Stem Cells
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		                        			Whole-Body Irradiation
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		                        			Radiation, Ionizing
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		                        			Bone Marrow Cells
		                        			
		                        		
		                        	
            

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